Report Formatting Guide

MARS Engine’s report module supports generating ODT-based documents (PDF, ODT) by merging template variables with data objects.

The template file MUST be in ODT format (unless using xlsx, sheet, or csv).

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General Text Variable Replacement

Declare a JavaScript object containing your data:

const data = {
  msg_1: "an ODT",
  msg_2: "different ways",
  msg_3: "images"
};

const tasks = { task_title: "wash the dishes" };

const res = report.odt("/link_to_file", { data, tasks });
write(res);

In the ODT template, use single curly braces to map fields:

{msg_1}
{msg_2}
{msg_3}

Example in-document variable mapping:

Result: The fields in the document get replaced by values from the data object.

Images

You can insert images dynamically:

1. Place a placeholder image in your ODT template (e.g. the MARS Engine logo).
2. Change its properties to have a variable name matching your data field, like data.img_1.

Example:

const data = {
  msg_1: "an ODT",
  msg_2: "different ways",
  msg_3: "images",
  img_1: 'binary data of the image'
};

const res = report.odt("/link_to_file", data);
write(res);

When you provide binary image data to img_1, the placeholder image in the template will be replaced:

Arrays

To repeat content like list items or table rows, use arrays in your data:

Example document formatting:

Example code:

const tasks = [
  { task_title: "Wash the dishes", task_completed: "finished" },
  { task_title: "Rest up", task_completed: "finished" },
  { task_title: "Meet with clients", task_completed: "not finished" },
  { task_title: "Table tennis with friends", task_completed: "not finished" },
];

const date = new Date();

const res = report.odt("/link_to_file", { tasks, date });
write(res);

Result: The template repeats sections for every item in the array.

Complex Nested Objects

You can work with deeper data structures like arrays of objects containing other objects.

Example code:

const people = [
  {
    name: "Mark",
    address: {
      street: "Example Street",
      number: 15,
      region: "Example Region",
      country: "Example Country"
    }
  },
  {
    name: "Rachel",
    address: {
      street: "Different Example Street",
      number: 16,
      region: "Different Example Region",
      country: "Different Example Country"
    }
  },
  {
    name: "Gustavo",
    address: {
      street: "Some arbitrary chicken restaurant",
      number: 18,
      region: "Different Example Region",
      country: "Different Example Country"
    }
  }
];

const res = report.odt("/link_to_file", people);
write(res);

Resulting document:

If you want finer control, you can define named tables in your template:

** Notes:**

• Always use ODT for template-based PDF/ODT generation.
• CSV and XLSX don’t require ODT.
• Use meaningful variable names to match your template design.
• Images and tables must be properly set up in the template with variable names.